Carlson, L. M. (2005). William J. Spillman and the birth of agricultural economics. University of Missouri Press.
Lua i Stíl Chicago (17ú heag.)Carlson, Laurie M. William J. Spillman and the Birth of Agricultural Economics. Columbia: University of Missouri Press, 2005.
Lua MLA (9ú heag.)Carlson, Laurie M. William J. Spillman and the Birth of Agricultural Economics. University of Missouri Press, 2005.
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